1. Field
Example embodiments relate to a composition, an organic insulator prepared using the same, an organic thin film transistor, and an electronic device. Other example embodiments relate to a composition, which includes a silane-based organic/inorganic hybrid material having a multiple bond, one or more organic metal compounds, and/or one or more organic polymers, thus making it possible to uniformly exhibit improved electrical properties upon application thereof to the insulating layer of a thin film transistor, an organic insulator prepared using the same, an organic thin film transistor and an electronic device.
2. Description of the Related Art
A thin film transistor (TFT) may be used as a switching device for controlling the operation of each pixel and a driving device for driving each pixel in a flat panel display, for example, a liquid crystal display (LCD) or an electroluminescent display (ELD). In addition, the TFT may be used for smart cards or plastic chips for inventory tags.
The TFT may include a source region and a drain region doped with a dopant having a relatively high concentration, a semiconductor layer having a channel region formed between the two regions, a gate electrode positioned in the region corresponding to the channel region while being insulated from the semiconductor layer, and a source electrode and a drain electrode respectively brought into contact with the source region and the drain region.
The semiconductor layer of the TFT may be formed of an inorganic semiconductor material, for example, silicon (Si). However, according to the recent trend toward the fabrication of relatively large, inexpensive, and flexible displays, an expensive inorganic material, requiring a high-temperature vacuum process, with an organic semiconductor material may be needed. Thus, research into organic thin film transistors (OTFTS) using an organic film as the semiconductor layer is being conducted. Such an OTFT may be advantageous because printing may be conducted at atmospheric pressure unlike a conventional silicon process, for example, plasma-enhanced chemical vapor deposition, and furthermore, performing a roll-to-roll process using a plastic substrate may be possible, consequently realizing inexpensive transistors.
The OTFT may have charge mobility equal or greater than amorphous Si TFTS, but the driving voltage and threshold voltage thereof may be undesirably higher. Accordingly, research has been directed toward insulating films to control the driving voltage of the OTFT and to reduce the threshold voltage thereof.
In this regard, methods of forming an organic insulator through chemical vapor deposition, physical vapor deposition, sputtering, or sol-gel coating using inorganic metal oxide or a ferroelectric insulator are known. However, these methods may be disadvantageous because most processes are conducted at temperatures as high as about 200° C.˜about 400° C., and thus, a plastic substrate for flexible displays may not be used. Further, upon the manufacture of devices, a conventional wet process including simple coating or printing may be difficult to implement, and furthermore, properties including charge mobility may remain unsatisfactory although the driving voltage decreases.
To overcome the above problems, an Si-based insulator containing an acryl group for improving charge mobility is disclosed in the related art. However, the TFT using the silane-based insulator containing the acryl group may undesirably cause hysteresis, in which the quantity of current varies depending on the magnitude of voltage, or over time.